WO2016135965A1

WO2016135965A1 - Beam dump device, laser device provided with same, and extreme ultraviolet light generation device

Info

Publication number: WO2016135965A1
Application number: PCT/JP2015/055930
Authority: WO
Inventors: 義明黒澤; 崇菅沼
Original assignee: ギガフォトン株式会社
Priority date: 2015-02-27
Filing date: 2015-02-27
Publication date: 2016-09-01
Also published as: JPWO2016135965A1; US10401615B2; JP6587676B2; US20170299857A1

Abstract

A beam dump device according to one embodiment of the present disclosure is provided with an attenuator module, a beam dump module, and a control unit for controlling the attenuator module and the beam dump module. The attenuator module includes the following: a first beam splitter which is disposed inclined, with respect to the light axis, at a first angle; a second beam splitter which is disposed inclined, with respect to the light axis, at a second angle which has an absolute value equal to the first angle and has a sign opposite thereto; a first beam damper on which the laser light reflected by the first beam splitter is incident; a second beam damper on which the laser light reflected by the second beam splitter is incident; and a first stage on which the first and second beam splitters are inserted into or retracted from the light path of the laser light. The beam dump module may include the following: a mirror which is disposed inclined with respect to the light axis of the laser light; a third beam damper on which the laser light reflected by the mirror is incident; and a second stage on which the mirror is inserted into or retracted from the light path.

Description

Beam dump device, laser device including the same, and extreme ultraviolet light generation device

The present disclosure relates to a beam dump device, a laser device including the beam dump device, and an extreme ultraviolet (EUV) light generation device.

In recent years, along with miniaturization of semiconductor processes, miniaturization of transfer patterns in optical lithography of semiconductor processes has been progressing rapidly. In the next generation, fine processing of 70 nm to 45 nm and further fine processing of 32 nm or less will be required. For this reason, for example, an exposure apparatus combining an apparatus for generating extreme ultraviolet (EUV) light having a wavelength of about 13 nm and a reduced projection reflective optical system to meet the demand for fine processing of 32 nm or less. Development is expected.

The EUV light generation apparatus includes an LPP (Laser Produced Plasma) system using plasma generated by irradiating a target material with laser light, and a DPP (Discharge Produced Plasma) using plasma generated by discharge. Three types of devices have been proposed: a device of the system and a device of SR (Synchrotron Radiation) method using orbital radiation.

Japanese Utility Model Publication No. 2-140501 JP-A-4-17992 Japanese Patent Laid-Open No. 10-326931 JP 2004-25293 A JP 2013-12465 A JP 2013-179330 A

Overview

A beam dump device according to an aspect of the present disclosure includes an attenuator module, a beam dump module, the attenuator module, and a laser control unit that controls the beam dump module, and the attenuator module is configured with respect to an optical axis of laser light. A first beam splitter disposed at a first angle with respect to the optical axis, a second beam splitter disposed at a second angle with the same absolute value as the first angle and an opposite sign with respect to the optical axis, A first beam damper arranged to receive the laser beam reflected by one beam splitter; a second beam damper arranged to receive the laser beam reflected by the second beam splitter; The second beam splitter is inserted into or retracted from the optical path of the laser beam. The beam dump module includes a mirror disposed to be inclined with respect to an optical axis of laser light, and a third beam damper disposed so that the laser light reflected by the mirror is incident thereon, A second stage for inserting or retracting the mirror with respect to the optical path, and the laser control unit selects the first and second beam splitters with respect to the optical path by controlling the first stage. The mirror may be selectively inserted into or retracted from the optical path by controlling or inserting the second stage.

A laser device according to another aspect of the present disclosure may include a master oscillator that outputs laser light, an amplifier that amplifies the laser light, and the beam dump device that is disposed on an optical path of the laser light. .

An extreme ultraviolet light generation apparatus according to still another aspect of the present disclosure is an extreme ultraviolet light generation apparatus that generates extreme ultraviolet light by irradiating a target material supplied to a plasma generation region with laser light, the laser light being The laser device for outputting, a chamber in which the plasma generation region is set, a condensing optical system for condensing the laser light in the vicinity of the plasma generation region, and supplying the target material in the vicinity of the plasma generation region A target supply device that collects the extreme ultraviolet light emitted from the plasma generated from the target material by being irradiated with the laser light.

Several embodiments of the present disclosure are described below by way of example only and with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing a configuration of an exemplary LPP type EUV light generation system. FIG. 2 is a schematic diagram illustrating a schematic configuration of an EUV light generation apparatus according to a comparative example. FIG. 3 is a schematic diagram illustrating a schematic configuration example of a laser apparatus including the beam dump device according to the first embodiment. FIG. 4 is a schematic diagram illustrating a schematic configuration example of the attenuator module according to the first embodiment. FIG. 5 is another schematic diagram illustrating a schematic configuration example of the attenuator module according to the first embodiment. FIG. 6 is a schematic diagram illustrating a schematic configuration example of the beam dump module according to the first embodiment. FIG. 7 is another schematic diagram illustrating a schematic configuration example of the beam dump module according to the first embodiment. FIG. 8 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the first embodiment. FIG. 9 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the first embodiment. FIG. 10 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the first embodiment. FIG. 11 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the first embodiment. FIG. 12 is a schematic diagram illustrating a schematic configuration example when the number of stages of the attenuator module according to the first embodiment is four. FIG. 13 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the second embodiment. FIG. 14 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the second embodiment. FIG. 15 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the second embodiment. FIG. 16 is a schematic diagram illustrating a schematic configuration example of an attenuator module according to the third embodiment. FIG. 17 is another schematic diagram illustrating a schematic configuration example of the attenuator module according to the third embodiment. FIG. 18 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the third embodiment. FIG. 19 is another schematic diagram illustrating a schematic configuration example of the beam dump device according to the third embodiment. FIG. 20 is a schematic diagram illustrating a schematic configuration example of the laser apparatus according to the fourth embodiment. FIG. 21 is a schematic diagram illustrating a schematic configuration example of the beam damper device according to the fifth embodiment. FIG. 22 is a schematic diagram illustrating a schematic configuration example of a frame according to the fifth embodiment. FIG. 23 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the first modification of the fifth embodiment. FIG. 24 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the second modification of the fifth embodiment. FIG. 25 is a schematic diagram illustrating a schematic configuration example of the beam dump device according to the sixth embodiment. FIG. 26 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to a modification of the sixth embodiment. FIG. 27 is a diagram illustrating an example of a cross-sectional profile image according to the sixth embodiment.

Embodiment

Contents 1. Outline 2. 2. Explanation of terms 3. Overview of EUV light generation system 3.1 Configuration 3.2 Operation 4. Extreme Ultraviolet Light Generation Device with Beam Dump Device: Comparative Example 4.1 Configuration 4.2 Operation 4.4 Problem 5. Embodiment 1
5.1 Schematic Configuration of Beam Dump Device 5.2 Configuration of Attenuator Module 5.3 Operation of Attenuator Module 5.4 Configuration of Beam Dump Module 5.5 Operation of Beam Dump Module 5.6 Detailed Configuration Example of Beam Dump Device 5 5.7 Operation of the beam dump device: When the laser beam is cut off 5.8 Operation of the beam dump device: During laser beam output 5.9 Operation of the beam dump device: During laser beam path adjustment 5.10 Operation of the beam dump device: Laser beam output 5.11 Effect 5.12 Modification of Embodiment 1 5.12.1 Other Configuration of Beam Dump Device 5.12.2 Other Configuration of Beam Dump Device: Operation Embodiment 2
6.1 Configuration 6.2 Operation Embodiment 3
7.1 Configuration 7.2 Operation 7.3 Effect 8. Embodiment 4
8.1 Configuration 8.2 Operation 8.3 Effect 9. Embodiment 5
9.1 Configuration 9.2 Operation 9.3 Effect 9.4 Modification 1 of Embodiment 5
9.4.1 Configuration 9.4.2 Effects 9.5 Modification 2 of Embodiment 5
9.5.1 Configuration 9.5.2 Effects 10. Embodiment 6
10.1 Configuration 10.2 Operation 10.3 Effect 10.4 Modification of Embodiment 6 10.4.1 Configuration 10.4.2 Operation 10.4.3 Effect

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment described below shows some examples of this indication, and does not limit the contents of this indication. In addition, all the configurations and operations described in the embodiments are not necessarily essential as the configurations and operations of the present disclosure. In addition, the same referential mark is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

1. Outline Embodiments of the present disclosure may relate to a beam dump device used in an EUV light generation device, a laser device including the beam dump device, and an EUV light generation device.

2. Explanation of Terms Terms used in the present disclosure are defined as follows.
A “droplet” may be a melted droplet of target material. The shape may be substantially spherical.
The “plasma generation region” may be a three-dimensional space preset as a space where plasma is generated.
The “upstream” of the laser beam may be the target position in the traveling path of the laser beam or the side closer to the light source. Further, the “downstream” of the laser beam may be a side farther from the light source than the target position in the traveling path of the laser beam.

3. General Description of EUV Light Generation System 3.1 Configuration FIG. 1 schematically shows a configuration of an exemplary LPP EUV light generation system. The EUV light generation apparatus 1 may be used together with at least one laser apparatus 3. In the present application, a system including the EUV light generation apparatus 1 and the laser apparatus 3 is referred to as an EUV light generation system 11. As shown in FIG. 1 and described in detail below, the EUV light generation apparatus 1 may include a chamber 2 and a target supply unit 26. The chamber 2 may be sealable. The target supply unit 26 may be attached so as to penetrate the wall of the chamber 2, for example. The material of the target substance supplied from the target supply unit 26 may include, but is not limited to, tin, terbium, gadolinium, lithium, xenon, or a combination of any two or more thereof.

The wall of the chamber 2 may be provided with at least one through hole. A window 21 may be provided in the through hole, and the pulse laser beam 32 output from the laser device 3 may pass through the window 21. In the chamber 2, for example, an EUV collector mirror 23 having a spheroidal reflecting surface may be disposed. The EUV collector mirror 23 may have first and second focal points. On the surface of the EUV collector mirror 23, for example, a multilayer reflective film in which molybdenum and silicon are alternately laminated may be formed. The EUV collector mirror 23 is preferably arranged such that, for example, the first focal point thereof is located in the plasma generation region 25 and the second focal point thereof is located at the intermediate focal point (IF) 292. A through hole 24 may be provided at the center of the EUV collector mirror 23, and the pulse laser beam 33 may pass through the through hole 24.

The EUV light generation apparatus 1 may include an EUV light generation control apparatus 5, a target sensor 4, and the like. The target sensor 4 may have an imaging function and may be configured to detect the presence, trajectory, position, speed, and the like of the target 27.

Further, the EUV light generation apparatus 1 may include a connection unit 29 that allows the inside of the chamber 2 and the inside of the exposure apparatus 6 to communicate with each other. A wall 291 in which an aperture 293 is formed may be provided inside the connection portion 29. The wall 291 may be arranged such that its aperture 293 is located at the second focal position of the EUV collector mirror 23.

Furthermore, the EUV light generation apparatus 1 may include a laser beam traveling direction control unit 34, a laser beam focusing mirror 22, a target recovery unit 28 for recovering the target 27, and the like. The laser beam traveling direction control unit 34 may include an optical element for defining the traveling direction of the laser beam and an actuator for adjusting the position, posture, and the like of the optical element.

3.2 Operation Referring to FIG. 1, the pulsed laser beam 31 output from the laser device 3 passes through the window 21 as the pulsed laser beam 32 through the laser beam traveling direction control unit 34 and enters the chamber 2. May be. The pulse laser beam 32 may travel along the at least one laser beam path into the chamber 2, be reflected by the laser beam collector mirror 22, and irradiate at least one target 27 as the pulse laser beam 33.

The target supply unit 26 may be configured to output the target 27 toward the plasma generation region 25 inside the chamber 2. The target 27 may be irradiated with at least one pulse included in the pulse laser beam 33. The target 27 irradiated with the pulsed laser light is turned into plasma, and radiation light 251 can be emitted from the plasma. The EUV light 252 included in the radiation light 251 may be selectively reflected by the EUV collector mirror 23. The EUV light 252 reflected by the EUV collector mirror 23 may be condensed at the intermediate condensing point 292 and output to the exposure apparatus 6. A single target 27 may be irradiated with a plurality of pulses included in the pulse laser beam 33.

The EUV light generation control device 5 may be configured to control the entire EUV light generation system 11. The EUV light generation controller 5 may be configured to process image data of the target 27 imaged by the target sensor 4. Further, the EUV light generation control device 5 may be configured to control the timing at which the target 27 is output, the output direction of the target 27, and the like. Further, the EUV light generation control device 5 may be configured to control, for example, the oscillation timing of the laser device 3, the traveling direction of the pulse laser light 32, the condensing position of the pulse laser light 33, and the like. The various controls described above are merely examples, and other controls may be added as necessary.

4). Extreme Ultraviolet Light Generation Device Equipped with Beam Dump Device: Comparative Example Next, an EUV light generation device according to a comparative example will be described in detail with reference to the drawings.

4.1 Configuration FIG. 2 is a schematic diagram illustrating a schematic configuration of an EUV light generation apparatus according to a comparative example. The EUV light generation apparatus illustrated in FIG. 2 includes a chamber 2, a laser apparatus 3, a laser light traveling direction control unit 34, and an EUV light generation control apparatus 5 in the same manner as the EUV light generation apparatus 1 illustrated in FIG. May be included.

The laser device 3 may include a master oscillator MO, one or more amplifiers PA1 to PA3, a laser control unit 41, and a beam dump device 1000. The amplifiers PA1 to PA3 may be arranged on the optical path of the laser beam 31 output from the master oscillator MO. The master oscillator MO and the amplifiers PA1 to PA3 may be connected to the laser control unit 41. The laser control unit 41 may be connected to the EUV light generation control device 5.

The beam dump device 1000 may be disposed so as to be movable between a blocking position where the laser beam 31 is blocked and a retracted position where the laser beam 31 is not blocked. The beam dump device 1000 may be connected to the cooling device 190.

The cooling device 190 may lower the temperature of the cooling medium. The cooled cooling medium may circulate between the beam dump device 1000 and the cooling device 190.

The chamber 2 may include a target supply unit 26, a target sensor 4, a window 21, a laser focusing optical system 50, a plate 54, an EUV focusing mirror 23, and a target recovery unit 28.

The laser beam 32 output from the laser beam traveling direction control unit 34 may be input to the laser focusing optical system 50 via the window 21. The laser focusing optical system 50 may be configured and arranged to focus the laser beam 33 on the plasma generation region 25. The laser focusing optical system 50 may include a laser beam focusing mirror 22. The laser beam condensing mirror 22 may be an off-axis parabolic mirror. The laser focusing optical system 50 may further include a convex mirror 51 facing the laser beam focusing mirror 22. The convex mirror 51 may be an elliptical mirror. The laser focusing optical system 50 may be fixed to the moving plate 52. A laser beam manipulator 53 may be connected to the moving plate 52.

Even if the laser beam manipulator 53 can move the moving plate 52 in the X-axis, Y-axis, and Z-axis directions so that the condensing position of the laser beam 33 can be moved to the position designated by the EUV light generation controller 5. Good.

The damper mirror 57 may be disposed on the laser light path downstream of the plasma generation region 25. The damper mirror 57 may be configured to reflect the laser beam 33 that has passed through the plasma generation region 25 toward the beam dump device 5000. The damper mirror 57 may collimate the incident laser beam 33. The damper mirror 57 may be an off-axis parabolic mirror. The damper mirror 57 may include a heater that heats the reflecting surface to the melting point of the target material.

The beam dump device 5000 may be disposed at a position where the laser beam 60 reflected by the damper mirror 57 is incident. The laser beam 60 may be incident on the beam dump device 5000 through a damper window 58 disposed on the chamber wall. The beam dump device 5000 may be connected to the cooling device 590.

The cooling device 590 may have the same configuration as the cooling device 190. Further, instead of arranging the cooling device 590, the cooling device 190 may be shared by the beam dump device 5000 and the beam dump device 1000.

4.2 Operation Next, an operation example of the EUV light generation apparatus shown in FIG. 2 will be described. When outputting EUV light, the EUV light generation control device 5 may cause the target supply unit 26 to output the target 27 in accordance with an EUV light output command from the exposure device 6. At this time, the beam dump device 1000 may be retracted to the retracted position.

The target sensor 4 may detect the target 27 and output the detection signal to the EUV light generation controller 5. The target detection signal may indicate the timing at which the target 27 has passed a predetermined position.

The EUV light generation controller 5 may output a light emission trigger delayed by a predetermined delay time with respect to the target detection signal to the laser controller 41 of the laser device 3.

The laser control unit 41 may output a laser output signal to the master oscillator MO when a light emission trigger is input. At this time, the laser control unit 41 may stand by in a state where the amplifiers PA1 to PA3 can be amplified. The master oscillator MO may output the laser beam 31 in synchronization with the laser output signal. The output laser light 31 may be amplified by the amplifiers PA1 to PA3, and then may pass through the laser light traveling direction control unit 34 and the window 21 and enter the chamber 2. The power of the laser beam 31 output from the laser device 3 may be several kW (kilowatt) to several tens kW.

The laser beam 32 incident on the chamber 2 may be collected by the laser focusing optical system 50. The focused laser beam 33 may be applied to the target 27 that has reached the plasma generation region 25. EUV light 251 may be emitted from the plasma generated by irradiating the target 27 with the laser light 33.

The EUV light generation control device 5 may adjust the irradiation position of the laser light 33 by controlling the laser light manipulator 53. Further, the EUV light generation controller 5 may change the delay time from the target detection signal to the light emission trigger.

The irradiation diameter of the laser beam 33 on the target 27 may be larger than the diameter of the target 27. In that case, a part of the laser beam 33 may be incident on the damper mirror 57 without being irradiated on the target 27.

The laser beam 60 reflected by the damper mirror 57 may be absorbed by the beam dump device 5000 via the damper window 58. The absorbed laser light 60 may be converted into heat. The heat generated thereby may be discharged to the outside by the cooling device 590.

There may be a case where the target 27 is not irradiated with the laser beam 33. For example, when the output of the laser device 3 is stabilized or the optical path is adjusted, the supply of the target 27 is stopped while the output of the laser beam 31 is continued, or the laser to the target 27 is intentionally changed by changing the delay time. There is a case where irradiation of the light 33 is avoided. In such a case, the laser beam 33 can enter the damper mirror 57 while maintaining the power without being irradiated to the target 27.

When the EUV light generation apparatus is stopped for a long time or during maintenance, the beam dump apparatus 1000 may be positioned at the blocking position.

When adjusting the laser beam traveling direction control unit 34 and the laser focusing optical system 50, the power of the laser beam 31 output from the laser device 3 may be reduced to about several W for safety. In that case, the laser control unit 41 may control the master oscillator MO and the amplifiers PA1 to PA3 so that the power of the laser beam 31 output from the laser device 3 is about several W. In the present disclosure, adjustment of the laser beam traveling direction control unit 34 and the laser focusing optical system 50 is referred to as laser beam path adjustment.

4.4 Problem When the laser light 31 having different power is output when the laser light path is adjusted and when the EUV light is output, as in the laser device 3 of the comparative example, the heat load on the optical components in the laser device 3 is changed to pulse energy. Can vary depending on. That is, the characteristic change of the optical component due to heat can be different between the laser light path adjustment and the EUV light output. Therefore, the beam divergence and the cross-sectional intensity distribution of the laser light 31 may be different between the laser light path adjustment and the EUV light output. It can be estimated that this is because the thermal lens effect of the optical component depends on the thermal load.

If the beam divergence and the cross-sectional intensity distribution adjusted at the time of adjusting the laser beam path fluctuate at the time of EUV light output, the target may not be irradiated with the laser beam 33 at the time of EUV light output. Therefore, a configuration capable of adjusting the laser beam path using the laser beam 31 having the same beam divergence and cross-sectional intensity distribution as that during EUV light output is required.

Further, in order to improve the throughput of the exposure apparatus 6, it is required to increase the output of the EUV light 252. In order to increase the output of the EUV light 252, it is necessary to increase the output of the laser beam 31. When the output of the laser beam 31 is increased, the capacity expansion of the beam dump device 1000 that receives the laser beam 31 and the beam dump device 5000 that receives the laser beam 33 may be required.

However, a commercially available beam damper may not be used depending on the output energy of the laser beam 31/33. In such a case, the high-capacity beam dump device 1000/5000 may be exclusively developed and produced, but this may lead to an increase in device cost.

Further, as shown in FIG. 2, the beam dump device 5000 can be attached to the outer wall of the chamber 2. In addition to the beam dump device 5000, many devices such as various measuring devices can be attached to the outer wall of the chamber 2. However, the area of the outer wall of the chamber 2 is finite. Therefore, when the beam dump device 5000 is increased in size with an increase in capacity, it may be difficult to attach a device including the beam dump device 5000 to the outer wall of the chamber 2.

Therefore, in the following embodiments, a beam dump device that makes it possible to perform laser optical path adjustment using a laser beam having a beam divergence and cross-sectional intensity distribution equivalent to that at the time of EUV light output, a laser device including the beam dump device, and an EUV 1 illustrates a light generation device. Further, in the following embodiment, a beam dump device that can be easily attached to the outer wall of the chamber 2 even when the capacity is increased will be exemplified.

5. Embodiment 1
First, a beam dump device according to a first embodiment, a laser device including the beam dump device, and an EUV light generation device will be described in detail with reference to the drawings.

5.1 Schematic Configuration of Beam Dump Device FIG. 3 is a schematic diagram illustrating a schematic configuration example of a laser device including the beam dump device according to the first embodiment. As shown in FIG. 3, the laser device 3 may include a beam dump device 100 and a cooling device 190 in addition to the laser control unit 41, the master oscillator MO, and the amplifiers PA1 to PA3.

The beam dump device 100 may include one or

more attenuator modules

110 and 120 and a beam dump module 130.

The

attenuator modules

110 and 120 and the beam dump module 130 may be connected to the cooling device 190 so that a cooling medium such as water supplied from the cooling device 190 can circulate.

The laser control unit 41 may be connected to the

attenuator modules

110 and 120 and the beam dump module 130, respectively. Specifically, the laser control unit 41 may be connected to the uniaxial stage of each module. The single axis stage will be described later.

5.2 Configuration of Attenuator Module FIG. 4 and FIG. 5 are schematic views showing a schematic configuration example of each attenuator module. FIG. 4 shows a case where the moving plate of each attenuator module is in the low output arrangement (first position), and FIG. 5 shows a case where the moving plate is in the high output arrangement (second position).

As shown in FIGS. 4 and 5, the attenuator module 110/120 includes an even number of

beam splitters

102A and 102B, a plurality of

beam dampers

104A and 104B, a moving plate 105A, a base plate 107A, and a single-axis stage 106A. May be.

The even-numbered

beam splitters

102A and 102B may be arranged so that the incident angles of the laser light 30 are opposite to each other. For example, when the incident angle θ1 of the beam splitter 102A is 45 °, the beam splitter 102B may be arranged so that the incident angle θ2 is −45 °.

Each of the

beam splitters

102A and 102B may be made of a substrate such as zinc selenide (ZnSe) or diamond. The surface of the substrate on which the laser beam 30 is incident may be provided with a coating having an appropriate reflectance. On the other hand, an antireflection film may be coated on the surface from which the laser beam 30 is emitted. The coating may be a multilayer film. Further, the substrate may be a parallel plane substrate or a wedge substrate.

The

beam splitters

102A and 102B may be held by

splitter holders

103A and 103B, respectively. Each

splitter holder

103A and 103B may be fixed to each of the

beam splitters

102A and 102B with respect to the moving plate 105A so that the inclination with respect to the traveling direction of the laser beam 30 is maintained. Inside each of the

splitter holders

103A and 103B,

flow paths

103a and 103b through which the cooling medium supplied from the cooling device 190 passes may be provided.

The

beam dampers

104A and 104B may be arranged at positions where the reflected

lights

30a and 30b reflected by the

beam splitters

102A and 102B respectively enter. Commercially available beam dampers may be used for the

beam dampers

104A and 104B.

In each of the

beam dampers

104A and 104B, a cone portion 104c and a pleated portion 104b may be provided. The cone part 104c may be a conical part. The cone portion 104c may have a shape that absorbs part of the incident laser light 30a / 30b and diffuses part of the laser light 30a / 30b around. The pleated portion 104b may have a shape that prevents the laser light 30a / 30b diffused by the cone portion 104c from diffusing out of the beam damper 104A / 104b. The pleated portion 104b may absorb the laser light 30a / 30b diffused by the cone portion 104c.

Each of the

beam dampers

104A and 104B may be provided with a flow path 104a through which the cooling medium supplied from the cooling device 190 passes. The channel 104a may be provided close to the surface of the cone portion 104c and the pleated portion 104b. The channel 104a may communicate with the channel 103a / 103b inside the splitter holder 103A / 103B.

The single axis stage 106A may be fixed to the base plate 107A. The single-axis stage 106A may be capable of moving the moving plate 105A with respect to the base plate 107A. The single-axis stage 106A may be configured by combining a ball screw and a motor, or may be configured by an extendable air cylinder or the like.

5.3 Operation of Attenuator Module Each of the

beam splitters

102A and 102B and each of the

beam dampers

104A and 104B may be cooled by circulating the cooling medium supplied from the cooling device 190.

The single-axis stage 106A may move the moving plate 105A in accordance with a signal from the laser control unit 41. The position of the moving plate 105A may include the low output arrangement (first position) shown in FIG. 4 and the high output arrangement (second position) shown in FIG.

As shown in FIG. 4, when the moving plate 105A is in a low output arrangement,

beam splitters

102A and 102B may be arranged on the optical path of the laser light 30. Each of the

beam splitters

102A and 102B may transmit a part of the laser light 30 and reflect a part thereof as reflected light 30a and 30b. As a result, the laser beam 30 with reduced energy may be output from each

attenuator module

110 or 120.

The reflected lights 30a and 30b may be incident on the

beam dampers

104A and 104B. Each of the

beam dampers

104A and 104B may convert the incident reflected

light

30a and 30b into heat. The heat generated in each of the

beam dampers

104A and 104B may be exhausted by the cooling device 190 using a cooling medium.

As shown in FIG. 5, when the moving plate 105 A is in a high output arrangement, the beam splitters 102 A and 102 B may be retracted from the optical path of the laser light 30. As a result, the laser beam 30 may be output from each

attenuator module

110 or 120 without energy reduction.

5.4 Configuration of Beam Dump Module FIGS. 6 and 7 are schematic diagrams illustrating an example of a schematic configuration of the beam dump module. FIG. 6 shows a case where the moving plate of the beam dump module is in the laser light blocking arrangement (third position), and FIG. 7 shows a case where the moving plate is in the laser light output arrangement (fourth position).

6 and 7, the beam dump module 130 may include a high reflection mirror 102C, a beam damper 104C, a moving plate 105C, a base plate 107C, and a uniaxial stage 106C.

The high reflection mirror 102C may be a copper substrate coated with gold or a silicon substrate coated with a highly reflective multilayer film.

The high reflection mirror 102C may be held by a mirror holder 103C. The mirror holder 103C may have the same configuration as the

splitter holders

103A and 103B. The mirror holder 103C may hold the high reflection mirror 102C so that the reflected light 30c enters the beam damper 104C. The mirror holder 103C may be fixed to the moving plate 105C.

Other configurations of the beam dump module 130 may be the same as those of the

attenuator modules

110 and 120.

5.5 Operation of Beam Dump Module The single-axis stage 106 C may move the moving plate 105 C according to a signal from the laser control unit. The position of the moving plate 105C may include the laser light blocking arrangement (third position) shown in FIG. 6 and the laser light output arrangement (fourth position) shown in FIG.

As shown in FIG. 6, when the moving plate 105 C is in the laser beam blocking arrangement, the high reflection mirror 102 C may be arranged on the optical path of the laser beam 30. The reflected light 30c from the high reflection mirror 102C may be incident on the beam damper 104C. As a result, the laser beam 30 may be blocked and the laser beam 31 may not be output from the beam dump module 130.

As shown in FIG. 7, when the moving plate 105 c is in the laser light output arrangement, the high reflection mirror 102 C may be retracted from the optical path of the laser light 30. As a result, the laser beam 30 may be output from the beam dump module 130 as the laser beam 31 without being blocked.

5.6 Detailed Configuration Example of Beam Dump Device FIGS. 8 to 11 are schematic views showing a schematic configuration example of the beam dump device 100 shown in FIG. As shown in FIGS. 8 to 11, the beam dump device 100 may include attenuator modules 110 and 120 (see FIGS. 4 and 5) and a beam dump module 130 (see FIGS. 6 and 7).

Here, one specification of the

beam splitters

102A and 102B and the beam dampers 104A to 104C in each module when the output of the laser device 3 is 20 kW is exemplified. The

attenuator modules

110 and 120 may have the same configuration.

In this case, the following specifications may be used.
・ Attenuator module 110
..Reflectance of beam splitter 102A = 33%, transmittance = 67%
..Reflectance of beam splitter 102B = 50%, transmittance = 50%
..Capacity of beam damper 104A = 10 kW
..Capacity of beam damper 104B = 10 kW
・ Attenuator module 120
..Reflectance of beam splitter 102A = 99%, transmittance = 1%
..Reflectance of beam splitter 102B = 90%, transmittance = 10%
..Capacity of beam damper 104A = 10 kW
..Capacity of beam damper 104B = 1 kW
・ Beam dump module 130
・・ Reflectance of high reflection mirror 102C = 99% or more ・ Capacity of beam damper 104C = 1 kW

In such a specification, a commercial product having a capacity of 10 kW or 1 kW may be used for each of the beam dampers 104A to 104C.

5.7 Operation of Beam Dump Device: When Laser Light is Cut Next, the operation of the beam dump device 100 will be described in detail with reference to the drawings. FIG. 8 is a schematic diagram illustrating an arrangement example in each module when the laser beam is blocked.

In this operation, the laser control unit 41 may receive a laser light cutoff signal from the EUV light generation control device 5, for example. The laser light cutoff signal may be a signal instructing to stop the output of the laser light 31 from the laser device 3.

As shown in FIG. 8, the laser control unit 41 may set the

attenuator modules

110 and 120 to a low output arrangement and the beam dump module 130 to a laser light cutoff arrangement as shown in FIG. Therefore, the laser control unit 41 may control the

uniaxial stages

106A and 106C of each module.

With this arrangement, the laser beam 30 can be incident on the

beam splitters

102A and 102B of the

attenuator modules

110 and 120 and the high reflection mirror 102C. At that time, the laser beam 30 can be attenuated by the

beam splitters

102A and 102B of the

attenuator modules

110 and 120, respectively. Thereafter, the laser beam 30 output from the attenuator module 120 can be diverted from the optical path for output by the high reflection mirror 120C.

Reflected light 30a to 30c by the

beam splitters

102A and 102B and the high reflection mirror 102C can enter the beam dampers 104A to 104C, respectively.

When the 20 kW laser beam 30 is incident on the beam dump device 100, the energy incident on each of the beam dampers 104A to 104C can be as follows.
・ Attenuator module 110
..Beam damper 104A: 6.6kW
..Beam damper 104B: 6.7kW
・ Attenuator module 120
..Beam damper 104A: 6.6kW
..Beam damper 104B: 60W
・ Beam dump module 130
..Beam damper 104C: 6.7W

In this case, even if a commercial product having a capacity of 10 kW or 1 kW is used for each of the beam dampers 104A to 104C, the energy of the reflected light 30a to 30c incident on each of the beam dampers 104A to 104C can be less than the respective capacity. As a result, the beam dump device 100 can block the 20 kW laser beam.

5.8 Operation of Beam Dump Device: During Laser Light Output FIG. 9 is a schematic diagram showing an arrangement example in each module when laser light is output (for example, during EUV light output).

In this operation, the laser control unit 41 may receive a laser light output signal from the EUV light generation control device 5, for example. The laser beam output signal may be a signal that instructs the output of the laser beam 31 from the laser device 3.

Referring to the laser light output signal, the laser controller 41 may set the

attenuator modules

110 and 120 to a high output arrangement and the beam dump module 130 to a laser light output arrangement as shown in FIG. Therefore, the laser control unit 41 may control the

uniaxial stages

106A and 106C of each module.

With this arrangement, the laser beam 30 may be output from the beam dump device 100 without entering the

beam splitters

102A and 102B and the high reflection mirror 104C.

Thus, at the time of laser beam output, for example, the 20 kW laser beam 30 can be directly output from the beam dump device 100 as the 20 kW laser beam 31.

5.9 Operation of Beam Dump Device: During Laser Optical Path Adjustment FIG. 10 is a schematic diagram illustrating an arrangement example in each module during laser optical path adjustment.

In this operation, the laser controller 41 may receive a laser beam path adjustment signal from the EUV light generation controller 5, for example. The laser optical path adjustment signal may be a signal for instructing or notifying execution of laser optical path adjustment.

In this operation, as shown in FIG. 10, the laser control unit 41 may set the

attenuator modules

110 and 120 to a low output arrangement and the beam dump module 130 to a laser light output arrangement. Therefore, the laser control unit 41 may control the

uniaxial stages

106A and 106C of each module.

With this arrangement, the laser beam 30 can be attenuated by the

beam splitters

102A and 102B of the

attenuator modules

110 and 120. The dimmed laser beam 30 can be incident on a subsequent beam delivery system 34 as a laser beam 31.

For example, when the

attenuator modules

110 and 120 have the specifications exemplified above, the power of the laser beam 31 output from the beam dump device 100 can be 6.7 W.

Thus, at the time of adjusting the laser beam path, for example, the 20 kW laser beam 30 can be output from the beam dump device 100 as the 6.7 W laser beam 31.

5.10 Operation of Beam Dump Device: During Adjustment of Laser Light Output FIG. 11 is a schematic diagram illustrating an arrangement example in each module when the power of the laser light is adjusted using the beam dump device.

In this operation, the laser control unit 41 may receive a laser light output adjustment signal from the EUV light generation control device 5, for example. The laser light output adjustment signal may be a signal that instructs adjustment (reduction) of the power of the laser light 31 output from the laser device 3. The adjusted power may be a predetermined power instructed by the EUV light generation controller 5, for example. The predetermined power instructed by the EUV light generation controller 5 may be, for example, 6.7 kW.

In this operation, as shown in FIG. 11, for example, the laser controller 41 may set the attenuator module 110 to a low output arrangement, the attenuator module 120 to a high output arrangement, and the beam dump module 130 to a laser light output arrangement. Therefore, the laser control unit 41 may control the

uniaxial stages

106A and 106C of each module.

With this arrangement, the laser beam 30 can be attenuated by the

beam splitters

102A and 102B of the attenuator module 110. The dimmed laser beam 30 can be incident on a subsequent beam delivery system 34 as a laser beam 31.

Thus, at the time of adjusting the laser beam output, for example, the 20 kW laser beam 30 can be output from the beam dump device 100 as the 6.7 kW laser beam 31.

5.11 Effect As described above, in the first embodiment, the laser light 30 is dimmed by the plurality of

beam splitters

102A and 102B of the

attenuator modules

110 and 120, and a plurality of unnecessary reflected lights generated due to the dimming are generated. Can be distributed to the beam dampers. Therefore, the capacity of each of the beam dampers 104A to 104C that receives the reflected lights 30a to 30c by the

respective beam splitters

102A and 102B and the high reflection mirror 102C can be reduced. Accordingly, for example, commercially available beam dampers can be used as the beam dampers 104A to 104C.

Further, in each

attenuator module

110 and 120, the even-numbered

beam splitters

102A and 102B may be arranged such that the incident angles of the laser light 30 are opposite to each other. In that case, it is possible to suppress a deviation between the optical axis of the laser light 30 incident on the

attenuator modules

110 and 120 and the optical axis of the laser light 30 emitted from the

attenuator modules

110 and 120. As a result, attenuator modules can be easily arranged in multiple stages, so that an arbitrary dimming rate can be easily realized.

Also, the

individual attenuator modules

110 and 120 can select a high output arrangement (no attenuation) and a low output arrangement (with attenuation). Therefore, the power of the laser beam 31 output from the laser device 3 can be adjusted to a desired power by controlling the arrangement state of the

attenuator modules

110 and 120. For example, the laser light 30 of several tens kW output from the amplifier PA3 in the final stage can be attenuated to the laser light 31 of several W and output.

In the first embodiment, the output of the master oscillator MO and the amplifiers PA1 to PA3 can be used as the output when the EUV light is output even when the laser light path is adjusted. Therefore, the thermal load of the optical elements from the master oscillator MO to the amplifier PA3 in the laser device 3 can be the same as that at the time of EUV light output. As a result, the beam divergence and cross-sectional intensity distribution of the laser light 31 at the time of laser light path adjustment can be substantially the same as those at the time of EUV light output. Thereby, since the optical path of the laser beam 32 and the like can be adjusted appropriately when EUV light is output, the irradiation of the laser beam 33 onto the target 27 can be stabilized.

Also, by combining the

attenuator modules

110 and 120 and the beam dump module 130, the energy of the reflected light 30c incident on the beam damper 104C of the beam dump module 130 can be reduced. Thereby, even when the laser beam 30 having a relatively high energy of about several tens of kW is output from the final stage amplifier PA3, a beam damper having a relatively small capacity can be used for the beam damper 104C. As a result, a commercially available beam damper can be used. Furthermore, since there is no limit to the number of attenuator modules, it is possible to easily cope with higher output of the laser device 3. Also in this case, since commercially available beam dampers can be used for the beam dampers 104A to 104C, it is possible to cope with high output at low cost.

5.12 Modification of Embodiment 1 In the above example, each

attenuator module

110 and 120 can output 6.7 kW of laser light 30 to 20 kW of laser light 30, but the present invention is not limited to this example. That is, the reflectance of each

beam splitter

102A and 102B of each

attenuator module

110 and 120 can be selected as appropriate. Further, the number of stages of the

attenuator modules

110 and 120 is not limited to two in the above example. That is, three or more attenuator modules may be mounted. The beam dump device may be configured to be able to output laser light 31 with several stages of energy by adjusting the number of stages of the attenuator module and the reflectivity of each of the

beam splitters

102A and 102B.

5.12.1 Other Configuration of Beam Dump Device FIG. 12 is a schematic diagram illustrating a schematic configuration example when the number of stages of the attenuator module is four. In the configuration shown in FIG. 12, the reflectivity of each

beam splitter

102A and 102B in each

attenuator module

110, 120, 140 and 150 may be determined according to a plurality of power values required for the laser light 31. .

Also, any of the beam dampers 104A to 104C in each module can be replaced with a beam profiler equipped with a power meter or a condensing optical system. In the example shown in FIG. 12, the beam damper 104B of the attenuator module 110 may be replaced with a power meter 104D. Further, the beam damper 104B of the attenuator module 150 may be replaced with the beam profiler 104E. The power meter 104D and the beam profiler 104E may be connected to the laser control unit 41 and the like, respectively.

5.12.2 Operation of Other Configuration of Beam Dump Device In FIG. 12, the laser control unit 41 may control the uniaxial stage 106A of each

attenuator module

110, 120, 140, and 150. Thereby, laser beams 31 with various powers may be output from the beam dump device 100.

Further, output signals of the power meter 104D and the beam profiler 104E may be input to the laser control unit 41. The laser control unit 41 may present the power value of the laser beam 31 to the operator when adjusting the laser beam path or blocking the laser beam. The presented power value may be calculated by the laser control unit 41 based on the output signal from the power meter 104D. At that time, the laser control unit 41 may calculate the power value using the dimming rates of the

beam splitters

102A and 102B.

Furthermore, the laser control unit 41 may present the profile of the laser beam 31 to the operator when adjusting the laser beam path or blocking the laser beam. The presented profile may be calculated by the laser control unit 41 based on the output signal of the beam profiler 104E.

The operator may adjust the laser beam path of the laser beam 31 based on the presented power value and profile. The laser control unit 41 may include a display for presenting power values and profiles.

The laser apparatus 3 may be provided with a mechanism for adjusting the position, posture, and the like of optical elements arranged on the optical path of the laser light 30 from the master oscillator MO to the amplifier PA3. In this case, the laser control unit 41 may control the position, posture, and the like of the optical element based on output signals from the power meter 104D and the beam profiler 104E when adjusting the laser beam path or blocking the laser beam.

6). Embodiment 2
Next, a beam dump device according to a second embodiment, a laser device including the beam dump device, and an EUV light generation device will be described in detail with reference to the drawings. In the following description, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

6.1 Configuration FIGS. 13 to 15 are schematic diagrams illustrating a schematic configuration example of the beam dump device according to the second embodiment. FIG. 13 is a top view of the beam dump device 200. 14 and 15 are side views of the beam dump device 200. FIG. FIG. 13 and FIG. 14 are schematic views showing an arrangement example in each module when the laser beam 30 is blocked. FIG. 15 is a schematic diagram illustrating an arrangement example in each module when laser light is output (for example, when EUV light is output).

As shown in FIGS. 13 to 15, the beam dump device 200 may include one or

more attenuator modules

210 and 220 and a beam dump module 230.

The single-

axis stages

206A and 206C of each module may be fixed to the

base plate

107A or 107C, respectively. Each

uniaxial stage

206A and 206C may move the moving

plate

105A or 105C in a direction different from that of the first embodiment with respect to the

base plate

107A or 107C. For example, as shown in FIGS. 14 and 15, the

uniaxial stages

206A and 206C may move the moving

plates

105A and 105C in the moving direction orthogonal to the optical element mounting surfaces of the

base plates

107A and 107C, respectively. . This moving direction may be the direction of gravity.

The moving

plates

105A and 105C may be guided by

linear guides

206a and 206c parallel to the moving direction of the

uniaxial stages

206A and 206C.

6.2 Operation When the laser beam is cut off, the laser control unit 41 sets the moving plate 105A of each

attenuator module

210 and 220 to a low output arrangement (first position) as shown in FIGS. The moving plate 105B may be arranged so as to block the laser beam (third position).

Further, at the time of laser beam output, the laser control unit 41 places the moving plate 105A of each

attenuator module

210 and 220 in a high output arrangement (second position) and moves the moving plate 105C of the beam dump module 230 as shown in FIG. A laser light output arrangement (fourth position) may be used.

The

linear guides

206a and 206c of each module may regulate the movement of the moving

plates

105A and 105C so that the moving

plates

105A and 105C are translated in the moving direction. Thereby, the angles of the optical element mounting surfaces of the moving

plates

105A and 105C with respect to the optical element mounting surfaces of the

base plates

107A and 107C may be maintained before and after the movement of the moving

plates

105A and 105C.

Other configurations, operations, and effects may be the same as those in the above-described embodiment.

7). Embodiment 3
Next, a beam dump device according to a third embodiment, a laser device including the beam dump device, and an EUV light generation device will be described in detail with reference to the drawings. In the following description, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

7.1 Configuration FIGS. 16 and 17 are schematic diagrams illustrating a schematic configuration example of an attenuator module according to the third embodiment. At least one of the plurality of attenuator modules mounted on the beam dump device 100 may be replaced with the attenuator module 310 in FIG. The attenuator module 310 may be able to continuously change the power of the laser beam 30 to be output.

As shown in FIGS. 16 and 17, the attenuator module 310 includes two

inner rotation stages

311A and 311B and two

outer rotation stages

312A and 312B in addition to the

beam splitters

102A and 102B and the

beam dampers

104A and 104B. May be. The inner

rotary stages

311A and 311B and the outer

rotary stages

312A and 312B may be mounted on the moving plate 105A. The moving plate 105A may be movable between the low output arrangement (first position) and the high output arrangement (second position) by the single-axis stage 106A similar to the first embodiment. However, the movement of the moving plate 105A may be guided by a linear guide 306a parallel to the moving direction of the uniaxial stage 106A.

The inner rotation stage 311A may be rotatable with an axis passing through the center as a rotation axis. The beam splitter 102A may be fixed to the inner rotary stage 311A using the splitter holder 103A. At this time, the beam splitter 102A may be fixed to the inner rotary stage 311A so that the rotation axis of the inner rotary stage 311A is positioned on the surface on which the laser beam 30 is incident. Such a configuration may be the same for the beam splitter 102B and the inner rotary stage 311B.

The outer rotation stage 312A may be rotatable about the same axis as the inner rotation stage 311A. The outer rotary stage 312 may have a disk shape or a donut shape. In the case of a donut shape, the inner rotary stage 311A may be rotatably accommodated in the central circular hole of the outer rotary stage 312. The beam damper 104A may be fixed at a position outside the inner rotary stage 311A in the outer rotary stage 312A. Such a configuration may be the same for the beam damper 104B and the outer rotary stage 312B.

The inner

rotary stages

311A and 311B and the outer

rotary stages

312A and 312B may be connected to the laser control unit 41, respectively.

As shown in FIG. 17, the outer rotary stage 312A may be configured to rotate at a rotation angle 2Φ that is twice the rotation angle Φ of the inner rotation stage 311A. This may be realized by control by the laser control unit 41, or may be realized by a gear ratio between a gear that rotates the inner rotary stage 311A and a gear that rotates the outer rotary stage 312A. Such a configuration may be the same for the inner rotary stage 311B and the outer rotary stage 312B.

Further, the inner rotary stage 311B may be configured to rotate in reverse to the rotation of the inner rotary stage 311A. For example, when the inner rotary stage 311A rotates by an angle Φ, the inner rotary stage 311B may rotate by an angle −Φ. This may be realized by control by the laser control unit 41, or may be realized by a gear that rotates the inner rotary stage 311A and a gear that rotates the inner rotary stage 311B.

7.2 Operation During laser beam path adjustment and laser beam output adjustment, the laser control unit 41 may place the moving plate 105A of the attenuator module 310 in a low output arrangement (first position) as shown in FIG.

Further, as shown in FIG. 17, the laser control unit 41 may control the

inner rotation stages

311A and 311B to change the incident angle of the laser light 30 to the

beam splitters

102A and 102B. At that time, the beam splitter 102A may rotate by the rotation angle Φ, and the beam splitter 102B may rotate by the rotation angle −Φ. By changing the incident angle of the laser beam 30 to each of the

beam splitters

102A and 102B, the reflectance and transmittance at each of the

beam splitters

102A and 102B can be changed.

Further, as the

inner rotation stages

311A and 311B rotate, the

outer rotation stages

312A and 312B may rotate twice the rotation angles 2Φ and −2Φ. Thereby, the arrangement of the

beam dampers

104A and 104B may be changed so that the reflected

lights

30a and 30b reflected by the

beam splitters

102A and 102B are incident on the

beam dampers

104A and 104B, respectively.

7.3 Effect With the above-described configuration, the power of the laser beam 30 output from the attenuator module 310 can be continuously and arbitrarily changed. Thereby, the output of the laser apparatus 3 can be changed continuously and arbitrarily.

Further, as described above, at least one of a plurality of attenuator modules (for example, the attenuator module 120) mounted on the beam dump device 100 may be replaced with the attenuator module 310 as shown in FIGS. Good.

In this case, when the laser beam is cut off, the laser control unit 41 sets the moving plate 105A of each

attenuator module

110 and 310 to a low output arrangement (first position) and moves the moving plate 105B of the beam dump module 130 as shown in FIG. May be a laser light blocking arrangement (third position).

At the time of laser beam output, the laser control unit 41 places the moving plate 105A of each

attenuator module

110 and 310 in a high output arrangement (second position) and moves the moving plate 105C of the beam dump module 130 as shown in FIG. A laser light output arrangement (fourth position) may be used.

At the time of laser beam path adjustment and laser beam output adjustment, the attenuator module 310 is placed in a low output arrangement, and the incident angles Φ and −Φ of the

beam splitters

102A and 102B with respect to the laser beam 30 are adjusted as shown in FIG. May be. Thereby, the power of the laser beam 30 output from the beam dump device 300 can be changed continuously and arbitrarily.

8). Embodiment 4
Next, a beam dump device according to a fourth embodiment, a laser device including the beam dump device, and an EUV light generation device will be described in detail with reference to the drawings. In the following description, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

8.1 Configuration FIG. 20 is a schematic diagram illustrating a schematic configuration example of a laser apparatus according to the fourth embodiment. The arrangement location of the attenuator module and the beam dump module exemplified in the above embodiment is not limited to the output stage of the laser device 3. That is, one or more attenuator modules 140 and / or beam dump modules 150 may be arranged on the optical path between the master oscillator MO and PA3. For example, as shown in FIG. 20, an attenuator module 160 and a beam dump module 170 may be arranged between the master oscillator MO and the amplifier PA1. Further, the one or more attenuator modules to be arranged may be any of the attenuator modules 110/120, 210/220 and 310 described above.

8.2 Operation In the configuration illustrated in FIG. 20, at the time of laser light output, the laser control unit 41 places the moving plate 105 A of the attenuator module 160 in a high output arrangement (second position), and moves the moving plate 105 C of the beam dump module 170. A laser light output arrangement (fourth position) may be used. However, when the attenuator module 310 is used as the attenuator module 160, the laser control unit 41 adjusts the rotation angle of each rotation plate while placing the moving plate 105A in a low output arrangement (first position), so that the laser device 3 May be adjusted.

When the laser beam is cut off, the laser control unit 41 sets the moving plate 105A of the attenuator module 160 to the low output arrangement (first position) and sets the moving plate 105C of the beam dump module 170 to the laser beam blocking arrangement (third position). Also good.

8.3 Effect For example, when a semiconductor laser such as a quantum cascade laser (QCL) is used for the master oscillator MO, the thermal load of the semiconductor laser may fluctuate if the output energy of the master oscillator MO is changed. Thereby, the oscillation wavelength of the master oscillator MO can be changed. On the other hand, according to the configuration of the fourth embodiment, since the master oscillator MO can always be oscillated with a constant energy, fluctuations in the oscillation wavelength of the master oscillator MO can be suppressed.

9. Embodiment 5
Next, a beam dump device according to a fifth embodiment, and a chamber device and an EUV light generation device including the beam dump device will be described in detail with reference to the drawings. In the fifth embodiment, a beam dump device attached to the chamber 2 of FIG. 2 is exemplified. In the following description, the same code | symbol is attached | subjected about the structure similar to embodiment mentioned above.

9.1 Configuration FIG. 21 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to the fifth embodiment. As shown in FIG. 21, the beam dump device 500 may include one or more beam dump modules 510 to 530. The beam dump device 500 may further include a termination module 540.

Each of the beam dump modules 510 to 530 may include a frame 501, a beam splitter 502, and a beam damper 104.

As shown in FIG. 22, the frame 501 may be a cheese tubular member made of metal or the like. The frame 501 may include a connection flange 501a at each of the three open ends. The sizes of the connection flanges 501a at the three open ends may be the same or different. However, even when the sizes are different, each connection flange 501a is preferably the same size as any one of the connection flanges 501a in the other frame 501.

Each connection flange 501a may include a plurality of bolt holes. In the connection flange 501a of the same size, the bolt hole diameter and the hole pitch may be common.

Each connection flange 501a may be a conflat flange. Con-flat flanges can be connected using metal packing. Therefore, airtightness in the beam dump device 500 can be ensured by using a conflat flange as the connection flange 501a. In that case, the chamber 2 may not include the damper window 58.

The three connection flanges 501a may each define an opening through which the laser beam 60 can enter and exit. One of the three openings may be used as an entrance through which the laser beam 60 enters the beam dump module 510/520/530. The other one may be used as an exit from which the laser beam 60 exits from the beam dump module 510/520/530. The remaining one may be used as an attachment port to which the beam damper 104 is attached.

A splitter holder 503 that holds the beam splitter 502 may be provided inside the frame 501. Inside the splitter holder 503, a flow path through which the cooling medium flows may be provided.

The splitter holder 503 has a position and an angle at which the reflected light 60a of the laser beam 60 incident from the incident port proceeds to the attachment port or the emission port, and the laser beam 60 transmitted through the beam splitter 502 proceeds to the emission port or the attachment port. The beam splitter 502 may be held. FIG. 21 illustrates a configuration in which the reflected light 60a travels to the attachment opening, and the laser light 60 transmitted through the beam splitter 502 travels to the exit opening.

For the beam splitter 502, an optical substrate exhibiting a high transmittance at the wavelength of the laser beam output from the CO ₂ laser may be used. The surface of the optical substrate may be provided with a coating for adjusting the reflectance. Alternatively, the beam splitter 502 may be an uncoated parallel plane substrate made of ZnSe. In that case, the reflectance when the laser beam output from the CO ₂ laser is incident at an incident angle of 45 ° can be about 20%.

The beam damper 104 may be the same as the beam dampers 104A to 104C described above. Therefore, a commercially available beam damper may be used for the beam damper 104. In that case, a dedicated or appropriate adapter may be used to attach the beam damper 104 to the connection flange 501a. Further, the flow path in the beam damper 104 may be connected to the cooling device 590.

The termination module 540 may be the beam damper 104. A dedicated or suitable adapter may be used to attach the end module 540 to the connection flange 501a. However, a beam damper different from the beam damper 104 may be used as the termination module 540.

Further, the termination module 540 may be a lid-like member that closes the exit of the frame 501 instead of the beam damper 104. In that case, in the example shown in FIG. 21, the reflectivity of the beam splitter 502 in the beam dump module 530 to which the termination module 540 is connected may be about 100%. However, when the mounting positions of the beam damper 104 and the termination module 540 (lid member) in the beam dump module 530 of FIG. 21 are switched, the beam splitter 502 in the frame 501 may be omitted.

The one or more beam damper modules 510 to 530 may be connected in a straight line. The beam dump module 510 located at one end of them may be connected to the chamber 2. The above-described termination module 540 may be connected to the beam dump module 530 located at the other end. Further, the beam dump modules 510 to 530 connected in a row may be arranged so that the connection flanges 501a used as attachment ports alternately face the opposite side. The connection between the

beam dump modules

510 and 520/520 and 530 and the connection between the beam dump module 530 and the termination module 540 may be fastening with bolts and nuts.

Here, for example, when the energy of the laser beam 60 incident on the beam dump device 500 is 10 kW, the specifications of the beam splitter 102 and the beam damper 104 of each of the beam dump modules 510 to 530 and the specifications of the beam damper 104 constituting the termination module 540 are used. May have the following specifications.
・ Beam dump module 510
..Reflectance of beam splitter 102 = 25%
..Capacity of beam damper 104 = 3 kW
・ Beam dump module 520
..Reflectance of beam splitter 102 = 33%
..Capacity of beam damper 104 = 3 kW
・ Beam dump module 530
..Reflectance of beam splitter 102 = 50%
..Capacity of beam damper 104 = 3 kW
Termination module 540
..Capacity of beam damper 104 = 3 kW

In the case of the above specifications, the energy of the laser beam 60 / 60a absorbed by each beam damper 104 can be estimated as follows.
-Beam damper 104 of the beam dump module 510: 2.50 kW
-Beam damper 104 of the beam dump module 520: 2.47 kW
-Beam damper 104 of the beam dump module 530: 2.51 kW
-Beam damper 104 of termination module 540: 2.51 kW

Thus, the four beam dampers 104 can absorb almost equal energy. Although the above-described specification is an example, a beam damper having a common specification can be used for each beam damper 104 by appropriately selecting the reflectance of the beam splitter 102. Further, the reflectance of the beam splitter 102 may be higher as the beam splitter 102 located downstream in the traveling path of the laser beam 60.

9.2 Operation The laser beam 60 reflected by the damper mirror 57 in the chamber 2 may enter the beam dump module 510 at the first stage of the beam dump device 500 via the damper window 58.

A part of the laser light 60 incident on the beam dump module 510 may be reflected as reflected light 60 a by the beam splitter 502. The reflected light 60a may be incident on the beam damper 104 attached to the connection flange 501a of the attachment port. A part of the reflected light 60a incident on the beam damper 104 may be absorbed by the cone part 104c (see FIG. 4 and the like), and the remaining part may be diffused and absorbed by the pleated part 104b.

On the other hand, the laser beam 60 attenuated when passing through the beam splitter 102 may enter the beam dump module 520 at the next stage through the exit port of the beam dump module 510.

As described above, the laser beam 60 may be attenuated by sequentially passing through the beam dump modules 510 to 530. Further, the laser beam 60 emitted from the exit of the beam dump module 530 at the final stage can enter the termination module 540 and be absorbed by the cone portion 104c and the pleated portion 104b.

9.3 Effects According to the fifth embodiment, the beam dump device 500 can be attached to the chamber 2 by securing an area equivalent to one beam dump module on the outer wall of the chamber 2. Also, a large capacity beam dump device 500 can be easily realized. That is, it is easy to add a beam dump module according to the energy of the laser beam 60.

Furthermore, a beam damper having a common specification can be used in a plurality of beam dump modules by appropriately selecting the reflectivity of the beam splitter in each beam dump module. This suggests that a commercially available beam damper can be used. As a result, the cost for developing and producing a large-capacity beam dump device 1000/5000 can be saved, so that an increase in device cost can be suppressed.

Furthermore, when a plurality of beam dump modules are arranged in series, the overall dimensions of the beam dump device 500 can be reduced by arranging the mounting ports so as to alternately face the opposite side. Furthermore, with such an arrangement, the optical path shift of the laser beam 60 inside the beam dump device 500 can be suppressed, so that the addition of the beam dump module is facilitated.

In addition, since the laser light 60 scattered by each part in the beam dump device 500 can be absorbed by the inner wall of the frame 501, external leakage can be suppressed.

Further, since each beam damper 104 and each beam splitter 102 are directly or indirectly cooled, damage can be suppressed over a long period of time.

9.4 Modification 1 of Embodiment 5
In the above-described fifth embodiment, the case where the energy of the laser beam 60 incident on the beam dump device 500 is 10 kW is exemplified. On the other hand, in the modification 1, the case where the energy of the laser beam 60 incident on the beam dump device is 20 kW is illustrated.

9.4.1 Configuration FIG. 23 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to the first modification. As shown in FIG. 23, the beam dump device 500A may further include

beam dump modules

550 and 560 in addition to the same configuration as the beam dump device 500. That is, the beam dump device 500A may have a configuration in which two

beam dump modules

550 and 560 are added to the beam dump device 500.

The beam dampers 104 of the beam dump modules 510 to 530, 550, and 560 do not have to have a common specification. For example, the capacity of the beam damper 104 of the subsequent beam dump module may be increased. Therefore, assuming that the energy of the laser beam 60 incident on the beam dump device 500A is 20 kW, the specifications of the beam splitter 502 and the beam damper 104 of each of the beam dump modules 510 to 530, 550 and 560 and the specifications of the beam damper 104 constituting the termination module 540 are provided. May have the following specifications.
・ Beam dump module 510
..Reflectance of beam splitter 102 = 12%
..Capacity of beam damper 104 = 3 kW
・ Beam dump module 520
..Reflectance of beam splitter 102 = 15%
..Capacity of beam damper 104 = 3 kW
・ Beam dump module 530
..Reflectance of beam splitter 102 = 25%
..Capacity of beam damper 104 = 5 kW
・ Beam dump module 550
..Reflectance of beam splitter 102 = 33%
..Capacity of beam damper 104 = 5 kW
・ Beam dump module 560
..Reflectance of beam splitter 102 = 50%
..Capacity of beam damper 104 = 5 kW
Termination module 540
..Capacity of beam damper 104 = 5 kW

In the case of the above specifications, the energy of the laser beam 60 / 60a absorbed by each beam damper 104 can be estimated as follows.
-Beam damper 104 of the beam dump module 510: 2.40 kW
-Beam damper 104 of the beam dump module 520: 2.64 kW
-Beam damper 104 of the beam dump module 530: 3.74 kW
-Beam damper 104 of the beam dump module 550: 3.70 kW
-Beam damper 104 of the beam dump module 560: 2.51 kW
-Beam damper 104 of termination module 540: 2.51 kW

In this way, the specifications of the beam damper 104 may be shared by the two

beam damper modules

510 and 520 in the previous stage. The specifications of the beam damper 104 may be shared by the four

beam damper modules

530, 550, and 560 in the subsequent stage. A commercially available beam damper can be used as the beam damper 104 having a capacity of 3 kW and a capacity of 5 kW. In this way, the beam damper 104 having a larger capacity may be used as the beam damper 104 located downstream in the traveling path of the laser light 60. The capacity of the beam damper 104 positioned upstream in the traveling path of the laser light 60 may be smaller.

9.4.2 Effect As described above, by setting the beam damper having a larger capacity as the beam damper 104 located downstream in the traveling path of the laser light 60, the installation area of the beam dump device 500A in the chamber 2 is not increased. The capacity of the beam dump device 500A can be increased. Further, by using a beam damper having a smaller capacity as the beam damper 104 located upstream in the traveling path of the laser beam 60, the space occupied by the beam dump device 500A in the vicinity of the chamber 2 can be reduced.

9.5 Modification 2 of Embodiment 5
In the fifth embodiment, the case where the beam dump modules 510 to 530 are arranged in series is illustrated. On the other hand, in the second modification, another arrangement of the beam dump modules 51 to 530 is illustrated.

9.5.1 Configuration FIG. 24 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to the second modification. As shown in FIG. 24, the beam dump device 500B may include beam dump modules 510 to 530 and a termination module 540, like the beam dump device 500. However, in the beam dump device 500B, the beam dump modules 510 to 530 may be bent and arranged in an L shape.

Further, the plurality of connection flanges 501a of the beam dump modules 510 to 530 may all have the same size and the same specification (arrangement of bolt holes, diameter, etc.).

9.5.2 Effects As described above, the plurality of beam dump modules can be connected in various arrangements, not limited to a linear arrangement. At that time, by making all the connection flanges 501a of the respective frames 501 common, the degree of freedom of arrangement of the beam dump modules can be further increased.

For example, auxiliary equipment such as a vacuum pump, various control devices, and various power supply devices can be arranged around the chamber 2. Therefore, the beam dump device 500 may be required to be arranged avoiding auxiliary equipment. As described above, when the shape of the beam dump device 500 protruding from the chamber is limited, the beam dump device 500B can be easily changed to the chamber 2 by appropriately changing the arrangement of the beam dump module as illustrated in the second modification. Can be installed.

10. Embodiment 6
In the beam dump device 500 illustrated in the fifth embodiment, the beam damper 104 of each module can be replaced with a laser light measuring instrument such as a power meter or a beam profiler. Therefore, in the sixth embodiment, a case where a power meter is used instead of the beam damper 104 of the termination module 540 is illustrated.

10.1 Configuration FIG. 25 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to a sixth embodiment. As shown in FIG. 25, the beam dump device 600 may include

beam dump modules

510 and 520 and a power meter 610 as a termination module. The

beam dump modules

510 and 520 may be similar to the

beam dump modules

510 and 520 described above.

The power meter 610 may be connected to the laser control unit 41. Further, the power meter 610 may be connected to the cooling device 590.

10.2 Operation The power meter 610 can measure the power of the incident laser beam 60. The power meter 610 may input the measured power of the laser beam 60 to the laser control unit 41.

The laser control unit 41 may hold the reflectance of the beam splitter 102 of each

beam dump module

510 and 520. The laser control unit 41 may calculate a dimming rate of the laser light 60 incident on the power meter 610 with respect to the laser light 60 incident on the beam dump device 600 based on the reflectance value of each beam splitter 102.

Further, the laser control unit 41 calculates the power of the laser light 60 incident on the beam dump device 600 (referred to as incident power) from the energy of the laser light 60 detected by the power meter 610 based on the calculated dimming rate. May be.

The calculated incident power of the laser beam 60 may be used as parameters for various controls by the laser control unit 41. For example, the laser control unit 41 may operate the laser light manipulator 53 based on the calculated incident power of the laser light 60. Thereby, the irradiation state of the laser beam to the target 27 may be controlled.

10.3 Effect The laser beam 33 can be irradiated with a larger diameter than the target 27. Therefore, the laser beam 33 that has passed around the target 27 can also enter the beam dump device 600. By measuring the power of the laser beam 33, the irradiation state of the laser beam 33 onto the target 27 can be estimated. Further, by operating the laser light manipulator 53 based on the estimated irradiation state, the irradiation state of the laser light 33 on the target 27 can be properly maintained.

10.4 Modification of Embodiment 6 In the modification, a case where a beam profiler is used instead of the beam damper 104 of the termination module 540 is illustrated.

10.4.1 Configuration FIG. 26 is a schematic diagram illustrating a schematic configuration example of a beam dump device according to a modification. As shown in FIG. 26, the beam dump device 600A may include beam dump modules 510 to 530 and a beam profiler 620 as a termination module. The beam dump modules 510 to 530 may be the same as the beam dump modules 510 to 530 described above. However, the arrangement may be bent in an L shape.

The laser beam 60 incident on the beam profiler 620 may be condensed by the condensing optical system 621. The condensing optical system 621 may be designed according to the damper mirror 57 (see FIG. 2) so as to transfer the image of the laser beam 33 in the vicinity of the plasma generation region 25 to the light receiving surface 622 of the beam profiler 620.

10.4.2 Operation The beam profiler 620 can measure a cross-sectional profile image of the incident laser beam 60. The cross-sectional profile image may be a cross-sectional profile image of the laser beam 33 irradiated on the target 27 in the plasma generation region 25.

The image data of the measured cross-sectional profile image may be input to the EUV light generation control device 5. The EUV light generation controller 5 may use image data as various control parameters. For example, the EUV light generation controller 5 may determine the irradiation state of the laser beam 33 on the target 27 based on the image data.

An example of a cross-sectional profile image is shown in FIG. The EUV light generation controller 5 determines whether or not the distance D between the center position O33 of the laser beam 33 and the center position O27 of the shadow 27S of the target 27 is within an allowable range in the cross-sectional profile image shown in FIG. May be.

The EUV light generation control device 5 may operate the laser light manipulator 53 so that the distance D becomes smaller when the distance D is not within the allowable range. Further, the EUV light generation controller 5 may control the delay time from the input of the target detection signal to the output of the light emission trigger so that the distance D becomes small.

10.4.3 Effect With the above-described configuration, the irradiation state of the laser beam 33 onto the target 27 can be properly maintained using the dimmed laser beam 60.

The above description is intended to be illustrative only and not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the embodiments of the present disclosure without departing from the scope of the appended claims.

Terms used throughout this specification and the appended claims should be construed as “non-limiting” terms. For example, the terms “include” or “included” should be interpreted as “not limited to those described as included”. The term “comprising” should be interpreted as “not limited to what is described as having”. Also, the indefinite article “a” or “an” in the specification and the appended claims should be interpreted to mean “at least one” or “one or more”.

2 ... chamber, 3 ... laser device, 4 ... target sensor, 5 ... EUV light generation control device, 21 ... window, 25 ... plasma generation region, 27 ... target, 30, 31, 32, 33, 60 ... laser light, 30a , 30b, 30c, 60a ... reflected light, 41 ... laser control unit, 50 ... laser focusing optical system, 51 ... convex mirror, 52 ... moving plate, 53 ... laser light manipulator, 57 ... damper mirror, 58 ... damper window, 100, 200, 300, 500, 500A, 500B, 600, 600A ... Beam damper device, 102, 102A, 102B ... Beam splitter, 102C ... High reflection mirror, 103A, 103B ... Splitter holder, 103C ... Mirror holder, 103a, 103b, 103c, 104a ... flow path, 104, 104A, 104 104C, beam damper, 104D, 610, power meter, 104E, 620, beam profiler, 104b, pleated portion, 104c, cone portion, 105A, 105C, moving plate, 106A, 106C, 206A, 206C, single axis stage, 107A 107C ... Base plate, 110, 120, 140, 150, 210, 220, 310 ... Attenuator module, 130, 230 ... Beam dump module, 190, 590 ... Cooling device, 206a, 206c, 306a ... Linear guide, 311A, 311B ... Inner rotary stage, 312A, 312B ... outer rotary stage, 501 ... frame, 501a ... connection flange, 510, 520, 530, 550, 560 ... beam dump module, 540 ... termination module, MO ... ma Data oscillator, PA1 ~ PA3 ... amplifier

Claims

An attenuator module;
A beam dump module, a laser control unit for controlling the attenuator module and the beam dump module;
With
The attenuator module is
A first beam splitter disposed at a first angle with respect to the optical axis of the laser beam;
A second beam splitter disposed with an absolute value equal to the first angle with respect to the optical axis and inclined at a second angle of opposite sign;
A first beam damper disposed so that the laser beam reflected by the first beam splitter is incident thereon;
A second beam damper disposed so that the laser beam reflected by the second beam splitter is incident thereon;
A first stage for inserting or retracting the first and second beam splitters with respect to the optical path of the laser beam;
Including
The beam dump module is
A mirror disposed to be inclined with respect to the optical axis of the laser beam;
A third beam damper disposed so that the laser beam reflected by the mirror is incident thereon;
A second stage for inserting or retracting the mirror with respect to the optical path;
Including
The laser control unit selectively inserts or retracts the first and second beam splitters with respect to the optical path by controlling the first stage, and controls the second stage to control the mirror. Selectively insert into or retract from the optical path,
Beam dump device.
The first stage translates the first and second beam splitters in a direction perpendicular to the optical axis;
The second stage translates the mirror in a direction perpendicular to the optical axis;
The beam dump device according to claim 1.
The beam dump device according to claim 1, wherein the laser control unit performs control to retract the mirror from the optical path in a state where the first and second beam splitters are inserted into the optical path.
The attenuator module is
A first rotating stage disposed on the first stage and mounting the first beam splitter;
A second rotary stage disposed on the first stage and mounting the first beam damper;
A third rotating stage disposed on the first stage and mounting the second beam splitter;
A fourth rotating stage disposed on the first stage and mounting the second beam damper;
Further including
The laser control unit controls rotation of the first to fourth rotation stages, and when the first rotation stage is rotated by a third angle, the second rotation stage is twice the third angle. A fourth angle is rotated, the third rotation stage is rotated by a fifth angle having the same absolute value as the third angle and an opposite sign, and the fourth rotation stage is twice the fifth angle. Control to rotate,
The beam dump device according to claim 1.
2. The beam dump device according to claim 1, further comprising a cooling mechanism that cools at least one of the first and second beam splitters, the mirror, and the first to third beam dampers.
A master oscillator that outputs laser light;
An amplifier for amplifying the laser beam;
The beam dump device according to claim 5 disposed on an optical path of the laser beam;
A laser device comprising:
An extreme ultraviolet light generation device that generates extreme ultraviolet light by irradiating a target material supplied to a plasma generation region with laser light,
The laser apparatus according to claim 6, which outputs the laser light;
A chamber in which the plasma generation region is set;
A condensing optical system for condensing the laser light in the vicinity of the plasma generation region;
A target supply device for supplying the target material in the vicinity of the plasma generation region;
A condensing mirror that condenses extreme ultraviolet light emitted from plasma generated from the target material by being irradiated with the laser light;
Extreme ultraviolet light generator equipped with.
One or more beam dump modules, a frame having an exit port and an attachment port configured to be connectable to an incident port and an incident port of another beam dump module, and held in the frame, the frame A beam splitter for branching the first laser beam incident through the incident port into a second laser beam that travels to the exit port and a third laser beam that travels to the mounting port; and the beam splitter attached to the mounting port A beam dump module including a beam damper; and
A termination module configured to be connectable to the exit of the beam dump module;
Beam dump device with